Diamond cut scoring system and method

Abstract

A gemstone rating system is provided particularly for rating the cut of diamonds in which particular cuts and features are measured and the results compared with and provided with a predetermined score depending upon deviations from a theoretical perfect cut; and wherein the deviation scores are summed and then subtracted from an initially perfect score to provide a universally comparable indication of quality of cut.

1. A method of classifying gemstones comprising:
 (a) mounting the gemstone upon a suitable support; 
 (b) directing electromagnetic waves of a limited wavelength at said gemstone, 
 (c) measuring the reflected electromagnetic waves in a manner such that the characteristics of the reflected electromagnetic radiation from individual facets of said gemstone are isolated and measured to represent the important reflectance characteristics of said facets, 
 (d) comparing each facet as measured with the facets of a theoretically perfect gem of the same character and subtracting from a theoretically perfect score of a predetermined number of points a preselected number of points dependent upon the variance of the actual facts with the theoretical facets, and 
 (e) at the completion adding up the remaining points for each facet and using the number as a sum of the value of the gem. 
 
   
   
     2. A method of classifying gemstones in accordance with  claim 1  wherein the gemstone is a brilliant cut diamond and the measurements are applied to the bottom main facet, the crown main facet, the brilliandeering facets and the roundness of the diamond. 
   
   
     3. A method of classifying gemstones in accordance with  claim 2  wherein the angle and depth of the bottom of the bottom main facet, the crown main facet, and brilliandeering facets are measured as well as the straightness of the brilliandeering facets. 
   
   
     4. A method of classifying gemstones in accordance with  claim 3  wherein the measurements begin with an attempt to measure the center of the girdle line and if successful the straightness of the main bottom and top main facets are also measured and angle and straightness of the star facets are also measured. 
   
   
     5. A method in accordance with  claim 4  wherein the initial numerical score is one thousand and measured deviations from the various elements are subtracted from such initial numerical score. 
   
   
     6. A method in accordance to  claim 5  in which a predetermined moderating quantity is added to the score to make the same determination with fewer criteria compatible with the score using additional criteria. 
   
   
     7. An arrangement for determining the grade of a gemstone with multiple cut facets comprising:
 (a) means for directing electromagnetic radiation at said gemstone positioned in a holder, 
 (b) means for monitoring reflected electromagnetic radiation from said gemstone and separating it into reflectance from various individual facets of the gemstone, 
 (c) means for comparing the reflected electromagnetic radiation reflectance from each measured facet with the reflectance from a theoretically perfectly cut gemstone, 
 (d) means for assigning a predetermined numerical point score to the facet deviations measured between the theoretically perfectly cut gemstone and actual gemstone, and 
 (e) means for subtracting the cumulative point score of deviations from a perfectly cut gemstone from an arbitrarily assigned total score for a perfectly cut gemstone. 
 
   
   
     8. An arrangement for determining the grade of a gemstone in accordance with  claim 7  wherein the various means for directing, mounting and comparing electromagnetic reflections are arranged for handling a brilliant cut diamond and the measurements are applied by suitable means with respect to the bottom main facet, the crown main facet, the brilliandeering facets and the roundness of the diamond. 
   
   
     9. An arrangement for determining the grade of a gemstone in accordance with  claim 8  wherein means for directing, mounting and comparing electromagnetic reflections are further arranged to measure the angle and depth of the bottom of the bottom main facet, the crown main facet, and brilliandeering facets as well as the straightness of the brilliandeering facets. 
   
   
     10. An arrangement for determining the grade of gemstone in accordance with  claim 9  wherein suitable measurement apparatus is provided to begin measurement with an attempt to measure the center of the girdle line and if successful further apparatus is used to measure the straightness of the main bottom and top main facets and the angle and straightness of the star facets are also measured. 
   
   
     11. An arrangement for determining the grade of a gemstone in accordance with  claim 10  wherein suitable means is provided to provide an initial numerical score of one thousand and various measured deviations from the theoretical perfect score are subtracted from such initial numerical score. 
   
   
     12. An arrangement for determining the grade of a gemstone in accordance with  claim 7  in which means is provided for introducing a predetermined moderating quantity to the score to make the same determination with few criteria compatible with the score using additional criteria.